Power mower with riding platform for supporting standing operator

ABSTRACT

A zero turning radius power lawn mower for operation by a standing occupant includes first and second independently driven and controlled rear drive wheels mounted on separate drive axles. A riding platform for supporting the standing occupant or operator is located between the first and second rear drive wheels. The rear drive wheels are independently driveable in both the forward and reverse directions at variable speeds so as to allow for substantially zero radius turning of the mower about a central turning point. The riding platform is positioned near this turning point or axis so that the standing occupant remains substantially unaffected by centrifugal force created during approximate zero radius turning of the mower thereby allowing the mower to take such turns at higher speeds. The low center of gravity created by the position of the riding platform for the standing operator also results in the mower having improved traction and being less likely to pop “wheelies” upon acceleration.

This is a continuation of application Ser. No. 09/519,420, U.S. Pat. No.6,789,304 filed Mar. 6, 2000 which is a continuation of Ser. No.09/426,746, filed Oct. 26, 1999 U.S. Pat. No. 6,094,897, which is adivisional of Ser. No. 09/054,460, U.S. Pat. No. 6,059,055 filed Apr. 3,1998, which is a divisional of Ser. No. 08/827,455, filed Mar. 28, 1997(now U.S. Pat. No. 5,809,755, which is a CIP of Ser. No. 08/726,927filed Oct. 3, 1996 Abn, which is a continuation of Ser. No. 08/615,518,filed Mar. 11, 1996 (now U.S. Pat. No. 5,600,944), which is acontinuation of Ser. No. 08/357,740 filed Dec. 16, 1994 (now U.S. Pat.No. 5,507,138) the entire content of which is hereby incorporated byreference in this application.

This invention relates to a power driven device. More particularly, thisinvention relates to a power lawn mower including a riding platform forsupporting a standing operator.

BACKGROUND OF THE INVENTION

Conventional hydraulically driven or hydrostatically controlled machinessuch as power lawn mowers include a pair of drive wheels, each of whichis independently operated by a hydraulic or hydrostatic pump coupled tothe mower's engine. A corresponding motor is provided for each drivewheel, each motor being powered by one of the pumps. Each pump includesa control lever for regulating fluid pressure and direction to itscorresponding motor. In such a manner the drive wheels of the powerdevice (e.g. lawn mower) are independently controlled so that each maybe rotated at variable speeds in both forward and reverse directions.

Accordingly, each drive wheel of hydrostatically controlled mowers maybe driven in either the forward or reverse direction and the mower maytherefore be turned through various angles. Hand levers for manipulationby the operator on such mowers are typically provided on handle membersfor moving the individual pump control levers into desired positions.The above described power lawn mowers are commonly referred to as zeroturning radius mowers because if operated in a particular orpredetermined manner, the right drive wheel and left drive wheel may berotated in opposite directions at similar speeds thereby allowing themower to conduct approximate zero radius turns about a central axis orpoint located between the drive wheels. This, of course, provides forimproved maneuverability in tight environments. Exemplary zero turningradius mowers are disclosed, for example, in U.S. Pat. Nos. 5,077,959;4,967,543; 4,991,382; and 4,920,733.

Conventional power mowers are generally divided into three separatecategories: (i) self-propelled walk-behind mowers; (ii) mowers operatedby a seated occupant; and (iii) mowers operated by a standing occupant.

U.S. Pat. Nos. 5,077,959; 4,967,543; 4,991,382 and 4,920,733 disclosetypical walk-behind power mowers including hydrostatically orhydraulically controlled rear drive wheels. Unfortunately, the operatorof walk-behind mowers such as these is forced to continually walk duringmowing operations, thereby leading to fatigue. This is, of course, adisadvantage associated with walk-behind mowers, especially in hillyenvironments. As a result of operator fatigue, mowers controlled bywalking operators are generally less productive over extended periods oftime. A further disadvantage of walk-behind mowers is that theoperator's feet are left unprotected and thus exposed to potentiallydangerous flying debris.

Turning now to power mowers operated by seated occupants, U.S. Pat. Nos.3,483,682; 4,487,006; 4,316,356; and 4,998,948 disclose typical suchmowers. Unfortunately, seated occupant operated mowers tend to havefairly high centers of gravity (i.e. they are top heavy) due to theposition of the operator's center of gravity which is far from. theground. Such high centers of gravity render mowers operated by seatedoccupants more likely to tip or roll. Because tipping and rolling ismore likely to occur as such mowers operate through turns or on hills,seated operators must be very careful in such environments and work atreduced speed. Operation at reduced speeds clearly leads to reducedproductivity of the mower. Additionally, seated operators have a hardtime ducking under low hanging tree limbs and the like because of thefixed position of the seat and thus the lower half of the operator'sbody. Furthermore, seat assemblies on such mowers necessarily increasethe overall cost of the mowers.

U.S. Pat. Nos. 2,354,576; 3,485,314 and 5,004,251 disclose power devicesoperated by standing occupants supported on trailers or sulkies. Theoperators of these devices (e.g. power mowers) are supported on sulkydevices or trailers removably attached to the mower. Thus, the standingoperator supporting trailing platforms of these patents are not actuallypart of the mower, but rather are mower attachments which must beremoved or folded up during mower transport. While the trailingplatforms or sulky devices of 2,354,576 and 5,004,251 provide for moweroperation by a standing occupant, they greatly extend the overall lengthof the mower system and are rather bulky in nature. Thus, the sulky orstanding occupant platforms of these patents must be disconnected orfolded up during transport of the mower. This is burdensome andinconvenient. A further problem with removable trailing platforms suchas those disclosed in 5,004,251 and 2,354,576 is that they significantlyextend the length of the mower thereby decreasing maneuverability intight spaces. Additionally, because these sulky or attachment devicesare not actually part of the mower, they must often be purchasedseparately thus increasing the overall cost of the mower system.

U.S. Pat. No. 4,878,339 discloses a power lawn mower including aselectively deployable riding platform for supporting a standingoperator or occupant. The mower of U.S. Pat. No. 4,878,339 may beoperated either as a walk-behind mower or alternatively as a standingoccupant/operator mower depending upon whether or not the standingoperator platform is deployed. In other words, because the platform isselectively deployable it is non-fixedly mounted to the mower.Unfortunately, in the walk-behind mode, this mower experiences theabove-referenced problems associated with typical walk-behind mowers.

In the standing operator mode (i.e. when the riding platform isdeployed), the power mower of U.S. Pat. No. 4,878,339 experiencesnumerous problems. Firstly, the position of the riding platformlengthens the overall length of the mower and renders it difficult tomaneuver in tight areas. Furthermore, while the platform of this patentprovides for a fairly low center of gravity, its location well behindthe rear drive wheel axis and extension substantially behind the reardrive wheels renders it more likely to bottom out or contact the groundwhen the mower goes over curbs, bumps, or the like.

If the power mower of U.S. Pat. No. 4,878,339 were operated so as toconduct a substantially zero radius turn, the rear drive wheels would beoperated in opposite directions at similar speeds and the centralturning point would be located between the rear wheels along the reardrive wheel axis. Because the standing occupant platform of the mower ofthe '339 patent is not located at or near this central turning axis(i.e. the platform is located well behind the rear drive wheel axis inthe standing operator mode), the operator is adversely affected bycentrifugal force created during approximate zero radius turns of themower. The standing operator is also more affected by centrifugal forcecreated during other mower turns. Due to this centrifugal force, thestanding operator or occupant of the mower of the '339 patent is forcedto take turns at slower speeds thus reducing the overall productivity ofthe mower over extended periods of time.

Another problem with the position of the platform of the U.S. Pat. No.4,878,339 mower is that its location creates a greater tendency for themower to “pop wheelies” upon acceleration, especially going up hills,because the mower's center of gravity is moved rearward when it isoperated by a standing occupant. The position of the platform of thispatent often necessitates the standing operator leaning forward prior toand during acceleration in order to avoid popping such wheelies andpossibly tipping over the mower.

It is apparent from the above, that there exists a need in the art for apower lawn mower operable by a standing occupant including a platformfor supporting the standing occupant, the platform being positioned onthe mower so as to result in the following advantages: (i) a low mowercenter of gravity resulting in improved drive wheel traction and lesssusceptibility to tipping or rolling; (ii) a lessened overall length ofthe mower so as to render it highly maneuverable in tight spaces andenvironments; (iii) a reduced tendency of the standing operator platformto bottom out or contact the ground when the mower goes over curbs,bumps, or the like; (iv) a platform positioned in a zero turning radiusmower such that the operator is substantially unaffected by centrifugalforce created during approximate zero radius turns, thereby allowing theoperator/mower to take such turns at higher speeds; (v) a platformpositioned in a manner such that the mower is less likely to popwheelies upon acceleration; etc. Each of the above advantages isaccomplished by positioning the standing operator platform of the mowersubstantially between the rear drive wheels.

It is the purpose of this invention to fulfill the above-described needsin the art, as well as other needs which will become apparent to theskilled artisan from the following detailed description of thisinvention.

SUMMARY OF THE INVENTION

Generally speaking, this invention fulfills the above-described needs inthe art by providing a zero turning. radius power mower for operation bya standing occupant, comprising:

an engine;

at least one cutting member powered by the engine;

first and second rear drive wheels each independently driveable in bothforward and reverse directions so as to allow for substantially zeroradius turning of the mower about a turning point when the rear drivewheels are driven in a predetermined manner; and

a riding platform for supporting the standing occupant, the ridingplatform being located close enough to the turning point or axis so thatthe standing occupant is substantially unaffected by centrifugal forcecreated during zero radius turning of the mower.

This invention further fulfills the above-described needs in the art byproviding a power mower for operation by a standing occupant,comprising:

an engine for driving a cutting member;

first and second rear drive wheels each rotatable about a common axis;

a riding platform mounted on the mower for supporting the standingoccupant, the platform being located between the first and second reardrive wheels during operation of the mower so that when the standingoccupant stands on the platform the standing occupant is between thefirst and second rear drive wheels at or near the axis, whereby theplatform is less susceptible to impacting the ground when going overbumps and the like.

It is an object of this invention to provide a zero radius turning mowerfor use by a standing occupant, wherein the occupant's foot platformextends forward of and underneath a frame (e.g. deck) section of themower so as to protect the occupant's feet from injury and conservevalued space.

It is another object of this invention to provide a unique handle barand control configuration for use with such a mower for the purpose ofenabling the standing occupant to more easily operate the mower inforward and reverse without losing his/her balance during the process ofdoing so.

It is still another object of this invention to provide front and sidestanding occupant thigh rests so that the standing occupant can resthis/her thighs against same during mower operation. In certain preferredembodiments, the hydraulic fluid tank is housed within a portion of thisthigh rest structure and an air cooling passage is designed to flowproximate same in order to help maintain the hydraulic fluid tank orreservoir at acceptable temperature(s).

It is still another object of this invention to provide a pump controllockout system for preventing accidental movement of the mower while theparking brake is engaged. Furthermore, according to certain embodiments,a wheelie bar member(s) is/are mounted to the rear of the mower in orderto reduce the possibility of extreme backward tipping of the mower whengoing up hills and the like.

Another object of this invention is to provide a deadman switch (i.e. oroperator presence control switch) that functions to stop cutting bladerotation beneath the mower deck in response to the operator stepping offof the foot platform.

It is still another object of this invention to fulfill theabove-described needs in the art by providing a zero turning radiusself-propelled power mower for operation by a standing occupant, theself-propelled mower comprising:

an engine;

at least one cutting member powered by said engine;

first and second rear drive wheels each independently drivable in bothforward and reverse directions so as to allow for substantially zeroradius turning of the mower about a turning axis when said rear drivewheels are driven in a predetermined manner, said turning axis beinglocated between said rear drive wheels, and wherein each of said firstand second rear drive wheels is rotatable about corresponding axles;

a first hydrostatically powered means connected to said first drivewheel and a second hydrostatically powered means connected to saidsecond drive wheel, said first and second hydrostatically powered meanseach being positioned proximate the axle of a corresponding wheel sothat said first and second means drive said first and second rear drivewheels, respectively, via their axles, said first and second means fordriving said rear wheels being located on opposite sides of said turningaxis;

a mower deck for housing said at least one cutting member, at least asubstantial portion of said mower deck and cutting member being locatedsubstantially forward of said first and second rear drive wheels;

a handle member including a hand grip portion, said hand grip portionlocated forward of said turning axis so that hands of the standingoccupant are normally located forward of said turning axis during zeroradius turns of the mower;

a foot platform for supporting the standing occupant, wherein said footplatform is located at a position relative to said hand grip portion andsaid turning axis so that a substantial portion of the standingoccupant's body may be located substantially on said turning axis duringzero radius turns of the mower and thus be substantially unaffected bycentrifugal force created during zero radius turns of the mower; and

wherein a substantial portion of said foot platform is located at anelevation below or substantially near an axis of at least one of saidrear drive wheels (or within the side profile of at least one of therear drive wheels) so as to create a low center of gravity of the mower.

This invention will now be described with respect to certain embodimentsthereof, accompanied by certain illustrations, wherein:

IN THE DRAWINGS

FIG. 1 is a top view of a zero turning radius power lawn mower accordingto certain embodiments of this invention.

FIG. 2 is a side elevational view of the power mower of FIG. 1 accordingto certain embodiments of this invention.

FIG. 3 is a side elevational view of a zero radius turning power moweraccording to another embodiment of this invention.

FIG. 4 is a side elevational view of a zero radius turning power moweraccording to still another embodiment of this invention.

FIG. 5 is a partial side elevational view of the lower portion of theFIGS. 3 or 4 mower.

FIG. 6 is a perspective view illustrating a handle configuration for usewith the zero radius turning mower of any of FIGS. 1-4.

FIG. 7 is a schematic perspective view illustrating a pump controllockout and braking system for use with the zero radius turning mower ofany of FIGS. 1-6.

FIGS. 8(a) and 8(b) are side elevational views illustrating a wheeliebar to be used in conjunction with the zero radius power turning mowerof any of FIGS. 1-7.

FIG. 9 is a side elevation/schematic view of a pivoting handle barsystem (including a stand/ride-on position and a walk-behind position)which may be used in conjunction with any of the mowers of FIGS. 1-8.

FIG. 10 is a side elevational view of an embodiment according to thisinvention including a deadman switch operatively associated with thefoot platform, this deadman switch being used in conjunction with any ofthe power mowers illustrated and described with respect to FIGS. 1-9herein.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THIS INVENTION

Referring now more particularly to the accompanying drawings in whichlike reference numerals indicate like parts throughout the severalviews.

FIGS. 1 and 2 are top and side views respectively of power lawn mower 1according to a first embodiment of this invention. Power lawn mower 1includes cutter assembly 3 and drive assembly 5.

Cutter assembly 3 includes engine 7 and cutter or mower deck 9. Mowerdeck 9 is mounted on and below frame 11 in front of engine 7 and enginedeck 13. Mower deck 9 is positioned close to the ground below enginedeck 13, and engine 7 in certain embodiments of this invention. Decks 9and 13 may be considered part of the frame by those of skill in the art.In the first embodiment as shown in FIG. 2, mower deck 9 is mounted onand connected to both engine deck 13 and frame 11. Frame 11 includes apair of substantially parallel frame members which extend longitudinallyalong mower 1. Mower deck 9 (or alternatively the mower wheels) isvertically moveable or adjustable so as to adjust the height of the cut.Deck 9 may be about 36-52 inches wide according to certain embodiments.

Mounted below mower deck 9 is one or more (e.g. three) cutting membersor blades 15 which rotate in a horizontal plane on vertical shaft(s) 17which are coupled to engine 7 by way of a belt drive assembly includingbelts 19 and 21. Three cutting blades 15 and corresponding shafts 17 areprovided in the first embodiment. Alternatively, as few as one blade 15and as many as five blades 15 may be provided in certain otherembodiments of this invention.

As shown in FIG. 1, drive belt 21 is coupled between the centralvertical shaft 17 and engine 7. Secondary blade belts 19 are connectedbetween the central vertical shaft 17 and the two peripheral shafts 17respectively. Thus, belts 19 are driven as a result of central shaft 17being driven by belt 21 which is coupled to and powered by engine 7.Cutter assembly 3 and its associated drive and engine 7 are conventionalin nature and therefore will not be discussed in further detail.

Drive assembly 5 includes engine deck 13 for supporting conventionalgasoline engine 7 (e.g. 2 cylinder, 22 HP, V-twin), rear drive wheels 23and 25, hydraulic (hydrostatic) pumps 31 and 33, motors 27 and 29, etc.Each drive wheel assembly optionally includes a protective fender 24.First and second rear drive wheels 23 and 25 are mounted either directlyor indirectly on the mower frame and are generally disposed on oppositesides of engine 7. Hydrostatic drive wheel motors 27 and 29 are mountedon mower 1 so as to drive wheels 23 and 25 respectively. Hydrostaticpumps 31 and 33 are mounted on either engine deck 13 or frame 11 asshown. Hydrostatic pump 31 is in communication with motor 27 and leftrear drive wheel 23 while hydrostatic pump 33 communicates withhydrostatic motor 29 and right rear drive wheel 25.

Each rear drive wheel 23 and 25 is mounted on its own drive axle 28 incertain embodiments of this invention. Axle 28 for wheel 23 may be partof motor 27 or alternatively may be separate from motor 27. The same istrue for axle 28 upon which rear wheel 25 is mounted. In certain otherembodiments of this invention, both rear drive wheels 23 and 25 may bemounted on a single supporting axle.

Hydrostatic pumps 31 and 33 are in conventional communication withhydrostatic motors 27 and 29 by way of, for example, a plurality ofhydraulic fluid hoses 6 and 8 disposed between each pump andcorresponding motor. Pumps 31 and 33 including known swash plates (notshown) generate hydraulic fluid pressure which is translated through oneof two hoses 6 and 8 connecting each pump (31 or 33) to its motor (27 or29). Hydraulic hoses 6 and 8 are coupled between each pump (31 and 33)and its motor (27 and 29) so as to allow hydraulic fluid to flow in bothdirections between each pump and its motor. One hydraulic hose (6 or 8)is for allowing hydraulic fluid to flow in one direction and the otherhose is for permitting the fluid to flow in the opposite direction.

For example, when fluid flows from pump 33 (or 31) to right drive wheelmotor 29 (or 27) via hose 6 and back to pump 33 through hose 8 thenmotor 29 and wheel 25 are driven in the forward direction. The speed atwhich wheel 25 is driven depends upon the rate of flow. However, whenthe fluid flow is reversed so that the fluid flows to motor 29 throughhose 8 and back to pump 33 through hose 6, then motor 29 and wheel 25are driven in the reverse direction.

Hydrostatic pumps 31 and 33 are driven by engine 7 by way of belts 35.Each pump 31 and 33 includes a conventional pump control lever 171 (e.g.see FIGS. 7 and 9) extending therefrom for permitting the standingoperator to control the speed and forward/reverse sense of each reardrive wheel via a hand lever 53 (or levers 107, 109, 117, 119, 121, 123)provided on the handle 39 of mower 1.

Alternatively, motors 27 and 29 could be positioned on frame 11 or deck13 adjacent engine 7 so that rear drive wheels 23 and 25 could insteadbe driven by chains or gears in a known manner, or other variable speeddevices may be attached to produce a zero radius turning mower.

Front caster wheels 41 are mounted at the front of mower deck 9 or frame11 by way of conventional caster assemblies 43. Each caster assembly 43includes caster pivot 45 and caster support 47. Caster assemblies 43allow mower 1 to be turned in any and all directions by rear drivewheels 23 and 25 as will be discussed more fully below.

Upwardly extending handles are provided for handling and manipulatingmower 1 and include a pair of handle members 39 and optionally a crossmember (not shown) secured between handle members 39 to hold themstructurally substantially parallel to one another in a spaced apartmanner. Each handle member 39 is connected to either frame 11 or mowerdeck 9 by way of bolts, screws, welds, or any other conventionalconnectors. Handle members 39 extend upwardly and slightly rearwardlytoward the standing operator according to certain embodiments of thisinvention so as to allow the operator to grip handles 39 and therebycontrol mower 1 via various controls (all of which are not shown)mounted on handles 39.

Speed and turning control assembly 51 is attached to handle members 39near the gripping portions thereof and includes speed control levers 53connected to each handle 39. Each speed control lever 53 which ispivotally mounted on a handle member 39 is conventionally coupled to oneof pumps 31 or 33 by way of their control lever 171 so that the lever 53mounted on left handle 39 is coupled to left pump 31 and controls thespeed of left rear drive wheel 23 and the other lever 53 which ismounted on right handle 39 controls the speed of right rear drive wheel25 via right hydrostatic pump 33 and motor 29.

The direction (forward/reverse) that each drive wheel 23 and 25 isdriven is also conventionally controlled by the standing operator viacontrol levers mounted on handles 39. Speed control levers 53 may alsobe used to control the direction or, alternatively, different levers 54can be coupled to pumps 31 and 33 for controlling direction in a knownmanner.

In operation, when engine 7 is running, hydrostatic pumps 31 and 33 aredriven at substantially the same speed. Hydraulic fluid under pressureis variably delivered to wheel motors 27 and 29 through first and secondconduits 6 and 8 extending between each pump and its respective motor.When the direction of fluid flow to the motor is through the firstconduit 6 and return flow to the pump through the second conduit 8, themotor (27 or 29) is driven in the forward direction so that itsrespective drive wheel (23 or 25) is also driven in the forwarddirection. On the other hand, when.the fluid flow is in the oppositedirection (i.e. going from the pump to the motor through the secondconduit 8 and returning to the pump through the first conduit 6) thiswill cause the motor to operate in the reverse direction so as to causeits respective drive wheel to be driven rearwardly. Whether or not drivewheels 23 and 25 are driven in either the forward or rearward directionis determined by the position of the above discussed control leversmounted on each handle member 39.

In such a manner, the standing operator may conventionally manipulatethe control levers so as to cause rear drive wheels 23 and 25 to either:(i) both be driven in the forward direction; (ii) both be driven in therearward direction; or (iii) one be driven in the forward direction withthe other being driven in the rearward direction.

In certain embodiments of this invention, a 1-2 gallon hydraulic fluidreservoir 151 for supplying pumps 31 and 33 is mounted (e.g. on andbetween handle members 39) substantially above pumps 31 and 33. Clutchand brake levers may also be mounted on handles 39 in certainembodiments of this invention.

Turning of mower 1 is carried out in one of three ways. Firstly, thestanding operator can cause mower 1 to turn in either direction bystopping one of the two rear drive wheels 23 and 25 (e.g. via clutch orbrake) while allowing the other to continue to be driven in either theforward or reverse direction. This may be carried out via theconventional handle 39 mounted control levers. Secondly, the standingoperator can cause the mower to turn by allowing drive wheels 23 and 25to be driven in the same direction (forward or reverse), but atdifferent speeds. Thirdly, the operator can turn mower 1 by causing reardrive wheel 23 to be driven in one direction and the other drive wheel25 to be driven in the opposite direction.

When rear drive wheels 23 and 25 are driven in opposite directions atsubstantially similar speeds, substantial zero radius turning isaccomplished about center axis or point 61 of circle 63. In zero radiusturning, mower 1 turns either leftwardly or rightwardly (depending uponwhich drive wheel is being driven forward) about central axis or point61. Thus, circle 63, as illustrated, shows the path along which thefront portion of mower 1 proceeds during substantial zero radiusturning. During substantial zero radius turning of mower 1, centralpoint/axis 61 of circle 63 is positioned along or near the rear drivewheel axis as shown in FIGS. 1 and 2. Accordingly, what is meant by“zero radius turning” is that mower 1 turns about a point 61 or axisdisposed between the drive wheels, and that point/axis 61 does not moveto any great extent during the turning.

Platform 71 for supporting the standing operator or occupant is disposedbetween rear drive wheels 23 and 25 along rear drive wheel axis 81 whichis defined by the rear drive wheel's axes of rotation. By positioningstanding platform 71 between rear drive wheels 23 and 25 substantiallyalong (i.e near) drive wheel axis 81 so as to include central point/axis61, the standing operator is substantially unaffected by centrifugalforce created during approximate zero radius turning of mower 1.

For example, if during a substantially zero radius turn of mower 1, theoperator was positioned at a location distant from central point/axis 61(e.g. along the front of mower deck 9 or far rearward of wheels 23 and25, for example) then he would be adversely affected by centrifugalforce created during the turn in that the operator would be pushed awayfrom point 61 by the centrifugal force. However, when a substantial partof the mass of the standing operator is located at or very near centralpoint/axis 61 due to the position of standing platform 71 and the handlemembers, he is substantially unaffected by such centrifugal force andtherefore can operate mower 1 so as to take such approximate zero radiusturns at higher speeds. Furthermore, by positioning the standingoperator on substantially flat platform 71 in close proximity to centralpoint 61, the operator is less affected by centrifugal force createdduring other (non-zero radius) turns undertaken by mower 1. The less theoperator is affected by such centrifugal force, the less fatigued hebecomes and the higher speeds he may allow or cause mower 1 to take suchturns.

Standing platform 71, as illustrated in FIG. 2, is positioned at anelevation vertically below or near rear drive wheel axis 81 therebyenabling the standing operator to apply his weight near the groundduring normal mower operations thus resulting in an effective mowercenter of gravity which is also close to the ground. This position ofplatform 71 below the tops of the rear wheels allows the standingoperator's weight to be focused at a point below the wheel tops andbelow or near rear drive axis 81 during typical operations of mower 1according to certain embodiments. In side hill environments, theoperator is thus permitted to shift his weight in order to compensatefor tipping tendencies. The resulting low center of gravity rendersmower 1 safer in that it is less susceptible to tipping or rolling,especially in hilly environments. Furthermore, this low center ofgravity focused along rear drive wheel axis 81 creates improved tractionof rear drive wheels 23 and 25, especially during side hill mowingoperations.

Platform 71 is surrounded or defined on its wheel sides by sidewalls 87and on its engine or front side by wall 89. Motors 27 and 29 are atleast partially encased behind sidewalls 87 and within compartments 88defined thereby. Alternatively, motors 27 and 29 may be fully encasedwithin compartments 88. Sidewalls 87 and 89 which define platform 71protect the operator's feet and lower legs from hazards associated withengine 7, motors 27, 29, blades 15, etc. while bottom wall 91 (or 163)of platform 71 protects the operator from hazards beneath the mower suchas blades 15 and flying debris.

The tops of sidewalls 87 define flat supports 93 upon which the standingoperator may position his feet when he needs to increase the weight onor improve the traction of one of the rear drive wheels. This isespecially helpful in side hill environments when improved traction isoften required on the top (or highest) rear drive wheel (25 or 23).Because the operator is standing on platform 71, he can easily shift hisweight to a side of the machine needing either additional tire tractionor additional weight for counterbalancing tipping. Alternatively, seatareas for the operator to sit during side-hill operations may beprovided about the areas illustrated at the top of sidewalls 87, inorder to counterbalance tipping tendencies.

Another advantage associated with the positioning of standing footplatform 71 between rear drive wheels 23 and 25 is that platform 71 isunlikely to bottom out or contact the ground when mower 1 goes overbumps, curbs, and the like. If, for example, platform 71 were locatedwell behind rear drive wheels 23 and 25 as in the prior art, it wouldsignificantly increase the likelihood of the platform bottoming out asthe mower traveled in a forward direction over a curb or other similarbump. However, positioning platform 71 between the rear drive wheels andnear or along tear drive wheel axis 81 in certain embodiments of thisinvention creates a situation where the possibility of standing operatorplatform 71 bottoming out as the mower goes over bumps, curbs, and thelike is greatly minimized.

The positioning of at least a portion of platform 71 between rear drivewheels 23 and 25 substantially along or near rear drive wheel axis 81also results in mower 1 being less susceptible to popping wheelies whenthe mower is accelerated, especially when going up hills. This isbecause the positioning of the standing operator's weight along or nearrear drive wheel axis 81 (as opposed to at a location behind the reardrive wheels) results in the mower's center of gravity being closer tothe front of the mower thereby resulting in it being less likely to popwheelies upon acceleration.

It is noted at this point that in the prior art, burdensomecounterweights (not shown) often had to be affixed to the front ofwalk-behind power mowers in order to move the mower's center of gravityforward so that the mower would not pop wheelies upon acceleration.

Yet another advantage of platform 71 being disposed between rear drivewheels 23 and 25 (as opposed to at a position rearwardly thereof) isthat there is less of a need for disposing such counterweights along thefront of the mower. This is because the operator's weight is locatedsubstantially near or along the rear drive wheel axis, and not at someposition rearwardly thereof which requires the positioning of largecounterweights on the front of the mower. Accordingly, the position ofplatform 71 also allows engine 7 to be located more rearwardly (e.g.over the toes or feet of the operator) than in the prior art, thusresulting in a larger mower and engine decks 9 and 13, and more room forrepairs and other such needs.

Mower 1, as described above, has a reduced overall length with respectto certain prior art mowers as a result of platform 71 being locatedbetween rear drive wheels 23 and 25. This allows the mower to be moreeasily and efficiently operated in tight locations and, in fact, permitsmower 1 to access regions previously unaccessible. The shorter overalllength of mower 1 also allows for more compact storage and transport.Furthermore, by allowing the standing operator to be between the rearwheels, the operator is less likely to impact obstacles such as treesand the like during mower operations in tight environments such aswoods, heavy brush, etc.

While certain preferred embodiments of this invention involve power lawnmowers, the standing operator platform of this invention may also beplaced between the rear drive wheels of other power driven devices suchas soil or lawn aerators, or other powered lawn maintenance devices.

According to certain alternative embodiments, a operator seat could bepositioned at or near point/axis 61 so as to make the mower aseated-operator type mower.

FIG. 3 is a side elevational view of a zero radius turning mower to beoperated by a standing occupant, according to another embodiment of thisinvention. As illustrated, the self-propelled power mower in FIG. 3includes front caster wheels 41, mower deck 9 beneath which the cuttingblade or blades 15 are rotatably mounted, engine deck 13 upon whichgasoline engine 7 is mounted (engine 7 is located forward of the reardrive wheels), a pair of rear drive wheels 23 and 25, foot platform 71for supporting the feet of the standing operator or occupant, and firstand second hydraulic pumps 31 and 33 for independently powering therespective rear drive wheels.

According to this embodiment, the zero radius turning stand-on mower ofFIGS. 3 and 6 further includes an improved handle assembly 101 includingrigid handle member 103 that is rigidly affixed to support member 105,and a pair of pivoting handle members 107 and 109, respectively,disposed on opposite sides thereof. Pivoting handle members 107 and 109rotate/pivot together about an axis or axes defined substantially atpoint 111. Handle system 101 allows the standing occupant to maintainhis/her hands on stationary non-pivoting rigid bar 103 during bothforward and reverse operations for improved balance/stability, whilepivotal levers 107 and 109 permit maximum leverage and stroke while theoccupant maintains a firm grip on the mower. Each lever 107, 109includes a right-hand portion and a separate and independent left-handportion (see FIG. 6). An elongated rod 145 extends from each of theright and left-hand levers to the corresponding pumps 31, 33.

Optionally, a second adjustable rigid handle member may be positioned onthe operator side of the forward levers 107, so that there would be aseparate rigid handle member for the forward and for the reversedirections. In such embodiments, a single pivoting lever 107 between thetwo rigid handle members is used for both forward and reverse of eachdrive wheel. Also, the positions of both rigid handle members (103) insuch embodiments may be adjustable.

For the occupant to cause the mower to move in the forward direction,the occupant simply pushes lever 107 forward 113 toward rigid handlemember 103, with the amount of movement forward of lever 107 dictatingthe speed of the corresponding (right or left) rear drive wheel in theforward direction. During full speed ahead operations, the user simplypivots and holds one or both of forward levers 107 flush against rigidmember 103. When the standing occupant releases lever 107, it is springbiased to pivot backward to-the position illustrated in FIG. 3 therebyplacing the corresponding rear drive wheel and pump in the neutralstate. In a similar manner, in order to cause a rear wheel(s) of thezero radius turning mower to operate in reverse, the standing occupantmerely pulls and pivots reverse lever 109 rearwardly 115 toward member103, with the amount of rearward pivoting of lever 109 about axis 111dictating the speed of the corresponding drive wheel in the reversedirection. Thus, for a constant full speed reverse movement of a rearwheel(s) of the mower, the operator may simply pull lever 109 backwardand hold it flush against the front surface of lever 103 until thestanding occupant desires to halt reverse operations. Upon the operatorletting go of lever 109, it will spring bias back into the neutralposition along with the corresponding lever 107, as illustrated in FIG.3. As can be seen, whether the standing occupant wishes to place rearwheel(s) of the mower in forward or reverse, his/her hands may alwaysremain in contact with rigid handle member 103 while manipulatingforward levers 107 (121, 123) and reverse levers 109 (117, 119), therebyimproving the stability of the system and improving the standingoccupant's balance on platform 71.

FIG. 6 is a close-up perspective view of handle control system 101, alsoillustrated in FIG. 3. Reverse lever(s) 109 includes right-hand lever117 and left-hand lever 119. As can be seen, right-hand reverse lever117 is independent and separately pivotable from left-hand reverse lever119. Rearward pivoting movement of lever 117 toward rigid handle member103 will cause the right rear drive wheel to move in a reversedirection, while rearward pivoting movement of left-hand reverse lever119 toward rigid handle member 103 causes the left rear drive wheel tomove in the reverse direction, with the amount of rearward movement ofthese levers determining the amount or speed of rearward rotation of thecorresponding drive wheel. At illustrated, lever 117 is connected vialinkage to pump 33, whil e lever 119 is connected via linkage to pump31.

Likewise, forward pivoting movement of right-hand forward lever 121toward member 103 will cause the right rear drive wheel 25 to move inthe forward direction, while forward pivoting movement of left forwardlever 123 causes the left rear drive wheel 23 to move or rotate aboutits axis in the forward direction. Movement of lever 121 (and 117)causes corresponding movement of lever member 171 of pump 33, whilemovement of lever 123 (and 119) causes movement of member 171 of pump31.

Adjustable elongated threaded members 125, that are pivotally attachedto both the rear and front levers 107 and 109 to interconnect same, areprovided for allowing the distance between the front and the rear leversto be adjusted. Thus, levers 107 and 109 are fully adjustable in orderto alter the reach and forward/reverse speed limits of the mower. Thestroke limit of each lever is reached when the lever at issue hits rigidmember 103 and is prevented from further movement. According to certainembodiments, the handle grip members of reverse levers 117 and 119 maybe designed to feel different (or be smaller) than rigid handle member103, so that the standing occupant would readily realize (withoutlooking) whether he/she was grasping the rigid member 103 or reverselever(s).

As illustrated in FIG. 6, broken rigid bar(s) 127 extend between thepair of spaced arms of support 105, and support the right-hand levers(117, 121) and the left-hand levers (119, 123). Thus, the right-handforward and reverse levers move together with one another when thecorresponding elongated member 127 pivots about axis 111. Likewise, thetwo left-hand levers 119 and 123 pivot together with one another. Thereis a break in the length of member 127 so that, for example, right lever121 is moveable separately from, and independent of lever 123.

Rigid handle member 103 is non-pivotally affixed to each elongated arm105 of the support, and extends between these arms, by way of fasteners131, or appropriate welding. Extension members 137 extend from eitherbar 127 or lever shafts 141 in order to connect the pair of control rods145 with their corresponding drive wheel levers 117, 119, 121, and 123.Control rods 145 extend downward from extension members 137 to thehydraulic or hydrostatic pumps 31, 33 that control rear drive wheelrotation, one rod 145 per pump. Thus, movement of one of levers 117-123in turn causes pivotal movement of a section of a bar 127 about axis111, thereby resulting in vertical movement of the corresponding controlrod 145 by way of member(s) 137. Movement of the control rods 145 causesthe corresponding pump 31, 33 to control the direction and speed of thecorresponding rear drive wheel 23, 25.

As shown in FIGS. 3, 4, and 6, support 105 includes a pair of spacedupwardly extending forwardly curved arms to which the handle mechanism101 is mounted. Furthermore, support 105 includes a rear plate 149 thatextends between (and connects) the spaced arms, and is provided for thepurpose of allowing the standing occupant to rest the front of his/herthighs or stomach against same during operation of the mower. Thus, afront thigh or stomach rest is defined by curved plate 149.Additionally, side thigh rest members 150 may be attached to support 105so as to aid an operator's stability when cornering larger than zeroradius turns, and also allow the operator to lean back slightly and tothe side during side hill operation in order to stay vertical (see FIG.3). Side leg or hip rests 150 are of a size so that when unexpectedmower movement forces the user to one side, the user would be stopped orsupported by rests 150. However, rests 150 may be small. enough so thatthe user may consciously slide around and beyond same during extremeside hill operation of the mower.

As shown in FIGS. 3-4, mounted within the housing defined betweensupport 105 sidewalls and thigh rest plate 149 is hydraulic fluid tankor container 151, including top 153 thereof. Plate 149 prevents thestanding operator's legs from coming into contact with tank 151, whichsometimes becomes quite hot during mower operation. Hydraulic linesconnect tank 151 to the hydraulic pumps 31, 33 located below.

The FIG. 4 embodiment differs from the FIG. 3 mower embodiment due tothe configuration of support 105. In the FIG. 4 embodiment, support 105again has a pair of spaced upwardly extending arms between which rearthigh resting plate 149 extends connecting the arms. However, in theFIG. 4 embodiment, support 105 is designed to receive air flow 155 whichfunctions to help maintain hydraulic tank 151 at an acceptabletemperature during mower operation (i.e. cools-the tank). Asillustrated, when the FIG. 4 mower is moving in the forward direction,air flows 155 through the handle assembly and is guided by the front ofrear plate 149 downwardly behind and around tank 151. This cooling airflow 155 is permitted to escape support 105 at an area 157 locatedvertically beneath tank 151.

FIG. 5 is an elevational view illustrating how the compartment of footplatform 71 undercuts the frame or engine deck 13 according to certainembodiments of this invention. See also FIGS. 2-4. As shown, the footsupporting surface 163 of platform 71 extends forwardly of andunderneath of a portion of frame or deck 13 until reaching front orforward wall 159 of the foot platform compartment. Thus, space is savedin that the engine deck, pulley and belt assembly 161, and/or pumps 31,33 are located vertically above each of the operator's feet and asubstantial portion (e.g. at least about 1-3 inches) of the footplatform. This both conserves space and functions to protect theoperator's feet from flying debris and the like. The foot platformcompartment illustrated in FIGS. 3-5 includes foot supporting surface163, front wall 159, top or upper wall 165, sidewalls 87, and wallportion 167 that connects top wall 165 with the top surface of the frameor engine deck. Top wall 165 extends rearwardly from front wall 159 atleast one-third of the total length of foot platform 71 to wall 167, andpreferably a length of at least about one-half thereof.

FIG. 7 is a perspective/schematic view of pump control lockout system169 according to an embodiment of this invention, pump lockout system169 being usable in conjunction with any of the self-propelled zeroradius turning mowers of FIGS. 1-6. Lockout system 169 is operativelyassociated with right-hand forward hand lever 121 and left-hand forwardhand lever 123 adapted to be held and manipulated by hands of thestanding operator, control rods 145, extension members 137 whichinterconnect control rods 145 and the forward levers, a pair ofelongated members 127 about which at least one of levers 121, 123 rotateor pivot, hydraulic (hydrostatic) pumps 31 and 33 for controllingmovement of the rear drive wheels, and pivoting arms or levers 171 whichpivot about axes 172 thereby allowing vertical movement of rods 145 tocontrol pumps 31 and 33. The lockout system 169 includes rotatableelongated bar member 173 which rotates about axis 174, hand manipulatedlever 175 to be mounted on support 105, elongated control rod 176,connecting member 177 for connecting hand lever 175 with rod 176,pivoting members 178 operatively connecting bar 173 with rod 176,elongated control rods 179, rear wheel brake bands 180 operativelyassociated with the rear drive wheels for the purpose of encirclingrespective brake drums on the rear drive wheels, and V-shaped members181 which pivot about axes 182 and connect brake bands 180 with controlrods 179. Optionally, lever 175 may be foot actuated and mounted to thebody of the mower proximate feet of the user. Alternatively, brake shoes(instead of bands 180) may be used to apply brake forces to the reardrive wheels.

Pump control lockout system 169 operates as follows. Firstly, hand lever175, resting against stop member 183, is illustrated in the “on” (i.e.pump locking and wheel braking) position in FIG. 7. When lever 175 isrotated about axis 184 from the off position to the “on” positionillustrated in FIG. 7, rod 176 and rods 179 are all caused to movevertically upward thereby causing members 181 to rotate clockwise (asillustrated) about axes 182 (for each rear drive wheel, or alternativelyfor only one of the rear drive wheels) thereby tightening brake band(s)180 around the drums (not shown) so as to apply a brake force to therespective rear drive wheel(s) and not allow the wheel to move. Duringmovement from the “off” to the “on” position, the forces of the brakesbias the lever 175 vertically downward after it has been pivoted beyondthe over center position vertically above pivot 184. Thus, the need forstop 183. In the “off” position, only gravity acts to pull lever 175vertically downward, to a stop.

When lever 175 is caused by the standing occupant to be pivotedcounterclockwise about axis 184 away from the on position downward tothe off position, this causes rod 176 to move vertically downward, whichin turn causes member 178 to pivot downward or counterclockwise alongwith bar 173 about axis 174 thereby causing control rods 179 to movedownward thereby loosening the pair of brake bands 180 as members 181pivot counterclockwise about axes 182.

Furthermore, when system 169 is in the illustrated “on” position, pumplocking members 185 that are rigidly affixed to rotating bar 173 arecaused to be in the position illustrated in FIG. 7, where recess orcutaway portions 187 defined in locking members 185 substantiallysurround and prevent pump levers 171 from pivotal movement in eitherdirection, thereby maintaining (locking ) pumps 31 and 33 (and the reardrive wheels) in neutral. When hand lever 175 is pivoted from the “on”position counterclockwise (as viewed in FIG. 7) about axis 184 towardthe “off” position, this causes both bar 173 and members 185 to rotatecounterclockwise about axis 174 thereby releasing or unlocking pumplevers 171 so that they may freely pivot about axes 172 in eitherdirection when caused to do so by handle members 121 and 123 (and/or117, 119). According to certain embodiments of this invention, bar 173is rotatably mounted between the spaced members of support 105.Accordingly, system 169 prevents accidental movement of the mower, andthe parking brakes 180 cannot be set until both pumps 31, 33 are inneutral.

FIGS. 8(a) and 8(b) illustrate a freely pivotal wheelie bar(s) 191 whichmay be used in conjunction with the zero radius turning mowers of any ofFIGS. 1-7 according to certain embodiments of this invention. As shown,a single rigid weighted wheelie bar member 191 is mounted proximate eachrear wheel 23, 25 of the zero radius turning mower by way of rigidsupport bar member 192. The purpose of the two pivotal wheelie bars 191mounted to the mower, is to prevent backward tipping of the mower duringuphill operation or movement of the mower. A rubber bumper 200 may beattached to either bar 191 or the mower in order to quiet operation.When the mower is moving on a flat and level surface, the wheelie bar191 adjacent each rear wheel hangs straight downward from point 192 sothat it forms an angle θ of approximately 90° (from about 80°-100°) withthe ground surface 190 (see wheelie bar position 193 in FIG. 8(a)).However, when the mower is caused. by the standing occupant to travel upa hill or incline, gravity causes each of the two wheelie bars 191 topivot backward about axis 192 rearwardly of the mower so as to enlargeto overall length of the mower and prevent backward tipping of same. Ifthe mower were to begin a backward tip when going up an incline, thebottom(s) 195 of member(s) 191 would contact the ground and prevent themower from flipping over. When going up hills, the bar(s) 191 pivotabout 192 and define an angle θ of from about 90°-180° (preferablybetween about 90°-135°) with the ground 190. For example, on a 10°incline, θ would be about 100°. Rigid stops 193 may keep θ between 90°and 135°. Angle θ is 90° when the mower is on horizontal ground.Optionally, an electric switch may be actuated when bar 191 contactsstop 193 or the like so that blade and/or engine operation.can bestopped during extreme incline conditions (i.e. stop the blades duringpotential flip conditions).

Because each of the two wheelie bars 191 is freely pivotable about axis192, both wheelie bars 191 are substantially always vertically alignedrelative to the horizontal, even when the mower is going up hills.Rearward pivoting of each bar 191 is limited by way of a stop member 193which is rigidly mounted to support piece 194 that protrudes fromsupport 105, so that if the mower begins to tip backward, the bottom 195of each wheelie bar 191 will engage the ground surface and prevent suchbackward tipping. FIG. 8(a) illustrates five different possiblepositions of each bar 191, depending upon the angle or level of thesurface 190 upon which the mower is traveling. Note that each wheeliebar 191 includes an elongated portion extending between axis 192 andenlarged weighted end portion 196.

FIG. 9 is a schematic/side elevation view of a pivoting handle barsystem which may be used in conjunction with any of the mowers discussedabove according to certain embodiments of this invention. This handlesystem is pivotal between a stand-on mode 302 and a walk-behind mode301. As illustrated, the handle bar system is attached to support 105(between the arms thereof at the top of same), and includes dashboard201, rigid handle member 103 attached thereto, pivoting handle members121 and 123 for controlling forward and/or reverse directions of themower, supporting bar(s) 203 pivotable about axis 205, a pair of stops207, pumps 31, 33 operatively connected to handle members 121, 123 byway of cable mechanism 145 and levers 171, and a pair of rotatablepulley members 211, 212 affixed to dashboard 201 and/or support 203 forthe purpose of maintaining cable 145 in a position as it leaves lever(s)137 such that lever(s) 137 are rotated in the same directional manner(e.g. counterclockwise about axis 127 to cause forward movement)regardless of whether dashboard 201 is in the right-hand walk-behindposition illustrated in FIG. 9, or alternatively pivoted to theleft-hand stand-on position illustrated in FIG. 9.

As shown in FIG. 9, the handle bar assembly, including dashboard 201which is pivotally mounted to supporting member 203 at pivot 221, may bepivoted between at least the two separate positions, about pivot axis205. When the handle assembly is in the position illustrated at theleft-hand side of FIG. 9 (i.e. closest to the front of the mower andforward of the rear drive wheels), it is in a ride-on mode wherein thestanding occupant positioned on platform 71 may manipulate the handleassembly and be substantially unaffected by centrifugal force duringzero radius turns of the mower. Alternatively, if the occupant shoulddesire to walk behind the mower instead of standing on it duringoperation, the occupant may simply pivot the handle assembly rearwardlyabout axis 205 until it reaches the position illustrated at theright-hand side of FIG. 9 (behind or at the rear drive wheels). When thehandle assembly is in the position shown at the right-hand side of FIG.9, the mower is in its walk behind mode wherein the operator may simplywalk behind the mower and manipulate the handle assembly to controlsame. Thus, the handle assembly pivots between a walk behind mode 301and a standing ride-on occupant mode 302. The degree of pivot about axis205 between the two positions may be from about 120° to 220°.

Stop members 207 halt the pivoting movement of support bar 203 aboutaxis 205 in either direction, as illustrated. A latch (not shown) isprovided to prevent unintentional movement of the handle bars in eitherwalk or ride modes. Furthermore, a spring 224 is provided at the end ofeach cable 145 near the corresponding pump lever 171 so that the FIG. 9controls are spring biased to the forward (or alternatively neutral)mower direction.

It is also important to note that pulley or guide members 211 and 212are mounted on dashboard 201 or member 203, each rotatable about itsrespective axis in certain embodiments. Due to the provision of pulleymembers 211 and 212, lever 137 is controlled in the same manner, and inthe same directions, regardless of whether the handle bar assembly is inthe ride-on mode or the walk behind mode. In the ride-on mode 302, cable145 winds around and is pressed against the outer periphery of member212, while in the walk behind mode 301 cable 145 winds around a portionof the periphery of pulley member 211. Each of members 211 and 212 isrotatably mounted upon dashboard member 201 or member 203.

At least one (possibly a pair) rigid metal rod 231 is provided in thepivoting handle assembly for the purpose of maintaining dashboard 201substantially level, or in substantially the same orientation relativeto the horizontal, in both the walk behind and ride-on modes, as well asduring the pivoting process between the two modes 301 and 302. Rod 231may be adjustable, for fine tuning purposes. Rod(s) 231 is pivotallymounted to support 105 at pivot axis 232 and is also pivotally mountedto dashboard 201 or any other part of the handle assembly at 233. Aswill be recognized by those of skill in the art, only one handleassembly is provided in the system. Thus, FIG. 9 illustrates a singlehandle assembly in two of its possible positions 301 and 302.

FIG. 10 is a side elevational view of a pivoting deadman switch platformassembly according to an embodiment of this invention, this deadmanswitch being usable in conjunction with foot platform 71 in any one ofthe above-discussed embodiments. As illustrated, the foot supportingsurface 163 (or 91) of platform 71 pivots upward and downward about axis241. Axis 241 may be made up of a hinge or the like, rigidly mounted tothe platform area or compartment of the stand-on mower of any one ofFIGS. 1-5. Pressure activated switch 243 is operatively associated withthe front portion of platform 71 and is located beneath a front area ofwall or surface 163 thereof. Biasing spring 245 is connected at one end246 to platform 71 and at the other end 247 to a top or sidewall of themower platform area or compartment. Thus, when the mower is not in useor when the standing occupant is not standing on platform 71, spring 245biases the front part of the platform upward about axis 241 so thatcutting blades of the mower do not rotate. Optionally, switch 243 may berod actuated and may be located above the foot platform (i.e. where therod for actuating the switch is connected to and/or moves with the footplatform).

Still referring to FIG. 10, deadman switch 243 is in an open state whenthe standing occupant is not on platform 71 and spring 245 is biasingthe front edge of the platform vertically upward about axis 241.However, when the occupant stands on platform 71 and presses the frontedge of surface 163 downward about axis 241 toward switch 243, theswitch is actuated or closed. When switch 243 is closed and the mower isrunning, the cutting blades (and optionally the engine, unless bladeswitch is in off position) of the zero radius turning mower arepermitted to rotate and cut grass. However, an opening of switch 243functions to immediately cut off power to the cutting blades andprevents further rotation thereof. Thus, as soon as the standingoccupant steps off of platform 71, switch 243 opens and the cuttingblades of the mower are no longer powered. Additionally, according tocertain further embodiments, switch 243 may function to cut off themower's engine when opened. Alternatively, switch 243 may be configuredso as to close when the operator steps off of the platform. In eitherevent, power to the cutting blades stops when the operator steps off ofthe platform.

It is noted that pivot axis 241 is located proximate the rear (i.e. inthe rear third or at the back of the platform) of platform 71 andsurface 163 thereof so as to be approximately located beneath the heelportion of the standing occupant's foot. Due to this positioning ofpivot axis 241, the operator must actually be in a proper moweroperating position in order to keep the blades running, and also thedeadman switch does not accidentally become opened or closed when thestanding occupant places additional weight on the balls or toes ofhis/her feet, which is natural during operation of the stand-on mowerdiscussed above. For example, if the pivot 241 were located elsewhere(e.g. at the center of the platform), the switch may be tripped if theuser simply had his/her toes at the rear of the platform.

Accordingly to alternative embodiments, a deadman pedal or pedals may beprovided at the front of the foot platform (on top of surface 163) so asto cut off blade rotation when the toes of the occupant's foot or feetlift up off of one or both of the pivoting deadman pedals.

According to further embodiments of this invention, the mower mayinclude a switch for immediately cutting engine power and/or applyingparking brake force to the rear wheels when the handle assembly issuddenly pivoted or otherwise forced forward as in a sudden mower stop.This could function to keep the mower from running over the occupant ifhe/she was to fall forward of the mower.

Once given the above disclosure, therefore, various other modifications,features, or improvements will become apparent to the skilled artisan.Such other features, modifications, and improvements are thus considereda part of this invention, the scope of which is to be determined by thefollowing claims.

We claim:
 1. A zero turning radius power mower comprising: an engine; atleast one cutting member powered by said engine; first and second reardrive wheels each independently driveable in both forward and reversedirections so as to allow for substantially zero radius turning of themower about a vertical turning axis; a foot platform structure forsupporting at least one foot of an occupant or an operator, wherein atleast a portion of said foot platform structure is located laterallyforward of a rear edge of one of said rear drive wheels; at least oneanti-wheelie member pivotally mounted to said mower proximate the rearend thereof via a pivot axis, said anti-wheelie member about said pivotaxis and thereby pivoting from a position from preventing the mower frompopping wheelies or flipping backward to an anti-wheelie position whenthe mower is caused to operate up a hill or incline; and wherein saidpivot axis of said at least one anti-wheelie member is located laterallyforward of a rear edge of one of said rear drive wheels and at anelevation above an elevation of a top edge of said one rear drive wheel.